The present invention relates to vehicle controlling apparatus and method for taking an evasive action to avoid collision with obstacles appropriately covering vehicle""s behaviors before and after the evasive action.
Several types of vehicle controlling apparatus have been developed and put into practical use for enhanced vehicle performance.
The followings are representatives of such vehicle controlling apparatus: a braking-force controller for appropriately applying braking force to wheels against any force exerted on a vehicle, for example, during cornering; a rear-wheel steering controller for controlling rear wheels in accordance with vehicle travelling conditions; a right-to-left torque-split controller for controlling torque split to right and left wheels in accordance with vehicle travelling conditions; and a torque-split controller for torque split between front and rear wheels by controlling differential power of a center differential between the front and rear wheels in accordance with vehicle travelling conditions.
Among other techniques also proposed recently is recognition of any obstacles in front, such as a vehicle travelling ahead, of a driver""s vehicle. Japanese Unexamined Patent Publication No. 7-21500, for example, discloses an automatic brake controller. In detail, a driver""s steering is always detected. When the driver""s vehicle and an obstacle are becoming close and it is determined that the driver""s vehicle cannot avoid collision with the obstacle only by usual braking control, the automatic brake controller controls braking force for each wheel for enhanced steering performance, or quick response to the driver""s steering.
The known apparatus achieves an appropriate control until the driver takes an evasive action, but not offering various fine controls after the evasive action.
Moreover, the known apparatus achieves high steering performance with automatic braking. It is, however, preferable that high steering performance is achieved by any vehicle controlling apparatus discussed above.
These vehicle controlling apparatus have to operate appropriately in accordance with complex operations such as evasive driving for avoiding an obstacle and then returning to the original position by a short time.
However, an erroneous obstacle information entered for evasive-driving support control for such apparatus could force a vehicle to enter an unnecessary evasive driving mode to change the vehicle characteristics so that a driver could have an uncomfortable feeling.
A purpose of the present invention is to provide vehicle controlling apparatus and method for an appropriate evasive action by accurately recognizing obstacles to a vehicle, precisely operating a controlling device for each vehicle behavior, and also restricting effects of any erroneously entered obstacle information to the vehicle control characteristics.
The present invention provides a vehicle controlling apparatus installed in a vehicle including: an obstacle recognizer to recognize an obstacle existing ahead of the vehicle for detecting information on the obstacle; a vehicle information detector to detect information on travelling conditions of the vehicle; a vehicle controller to change steering performance of the vehicle for controlling behaviors of the vehicle; an evasive-driving determiner to determine whether the vehicle can avoid collision with the obstacle only by a driver""s braking operation based on at least the information on the obstacle and the vehicle; an evasive-driving controller to control the vehicle controller to enter into an evasive driving mode in accordance with a driver""s steering operation and the vehicle behaviors when it is determined that the vehicle cannot avoid collision with the obstacle only by the driver""s braking operation and also control the vehicle controller to change a control operation of the vehicle controller in the evasive driving mode in accordance with the driver""s steering operation and the vehicle behaviors; and an evasive-driving condition determiner to determine whether the vehicle has been maneuvered for avoiding collision with the obstacle, wherein the evasive-driving controller releases the vehicle from the evasive driving mode when it is determined that the vehicle has not been maneuvered for avoiding collision with the obstacle even though the vehicle has reached the obstacle in the evasive driving mode.
Moreover the present invention provides a vehicle controlling method including the steps of: recognizing an obstacle existing ahead of a vehicle to detect information on the obstacle; detecting information on travelling conditions of the vehicle; changing steering performance of the vehicle for controlling behaviors of the vehicle; determining whether the vehicle can avoid collision with the obstacle only by a driver""s braking operation based on at least the information on the obstacle and the vehicle; entering into an evasive driving mode in accordance with a driver""s steering operation and the vehicle behaviors when it is determined that the vehicle cannot avoid collision with the obstacle only by the driver""s braking operation; changing the steering performance of the vehicle in the evasive driving mode in accordance with the driver""s steering operation and the vehicle behaviors; determining whether the vehicle has been maneuvered for avoiding collision with the obstacle; and releasing the vehicle from the evasive driving mode when it is determined that the vehicle has not been maneuvered for avoiding collision with the obstacle even though the vehicle has reached the obstacle in the evasive driving mode.